The present invention is an advance in the art of papermaking. This invention enables layered paper and tissue to be made more efficiently and with greater cross-machine direction basis weight uniformity.
In the manufacture of paper sheets, including creped tissue paper, a headbox is used to deposit the papermaking stock onto a forming wire, where the stock is partially dewatered to form a paper web. In this process it is often advantageous to form the paper web in distinct layers of different fiber compositions. Layered headboxes having internal dividers are well known in the art to achieve this objective. In some of these layered headboxes, the internal dividers end before the slice opening. In others, they extend beyond the slice opening. Layered headboxes are disclosed in Betley et al. U.S. Pat. No. 3,843,470, Wahren U.S. Pat. No. 4,070,238, Justus U.S. Pat. No. 4,141,788, Farrington, Jr. U.S. Pat. No. 5,129,988, and Allen U.S. Pat. No. 5,133,836, all of which are incorporated herein by reference.